This invention relates generally to an interluminal prosthesis for the repair of body conduits. More particularly, the invention relates to an interluminal device for insertion into a body conduit for repair of damaged portions thereof.
The present invention is particularly useful for the repair of an aortic aneurysm. Aortic aneurysms are an abnormal dilation of the aorta that if not repaired can burst and kill the patient. Interluminal devices for repairing these aneurysms are known in the art. The devices are typically comprised of flexible grafts that are inserted into the aorta via open surgery.
The surgical procedures for repairing aneurysms are major undertakings that replace a portion of the aorta with a prosthetic device. Generally, these prosthetic devices are comprised of a synthetic tube or graft, typically formed of Dacron, Teflon or other suitable material. In particular procedures, the aorta is clamped above and below the aneurysm cutting off the normal flow of blood through the aorta. The aneurysm portion of the aorta is removed and a graft having a diameter approximately the same size as the normal diameter of the aorta is sutured to the two cut ends of the aorta to structurally replace the aneurysm. Generally, this is a very difficult procedure for the patient and requires extensive recovery time. Also, the incision extends from the xiphoid to the pubic bone and accompanies a significant amount of complication. Thus, the patient has a significant incision extending down the abdomen and must recover from this intrusive procedure.
In order to overcome the difficulties with these surgeries, several procedures have been suggested for the insertion of a raft through the femoral and iliac arteries. These procedures involve the compression of the graft so that it can be inserted through the femoral artery, up the iliac artery and then, when it is positioned in the aorta across the aneurysm, the graft is expanded with stents. This interluminary insertion of the graft can result in a significant reduction in the trauma and complication of the surgery.
The prosthetic devices used in these procedures are comprised of a generally tubular graft for insertion into the aorta with two integral legs extending therefrom for extending from the aorta into the iliac arteries.
U.S. Pat. No. 5,720,776, for example, discloses a prosthesis assembly for placement at an aneurism in the bifurcated lumen of the aorta and the iliac arteries extending therefrom. The prosthesis assembly includes a single lumen graft or a bifurcated lumen graft having a main body and ipsilateral and contralateral limbs extending therefrom. The main body and ipsilateral and contralateral limbs each have a spring assembly around their orifices for conforming that portion of the graft to the wall of the vessel lumen. The main body spring includes a barb with first and second arms for securely anchoring the spring assembly to the vessel wall. The ipsilateral and contralateral spring assemblies also include the barb with only a single attachment arm for anchoring the spring assembly to the vessel wall.
Similarly, U.S. Pat. No. 5,755,770 discloses an arterial interluminal prosthesis for repairing aneurysm and connecting to iliac arteries. The prosthesis includes a generally tubular, flexible graft with a proximate end and two distal ends. Each of the distal ends includes integral legs which bifurcate from the graft. The prosthesis includes a first stent disposed within and emerging from the proximate end and is adapted to attach to the aorta. A hem terminating in the distal end of the graft is inverted within the leg. A second stent having a proximal end and distal end can be attached to the interior of the distal end of the cuff so that upon withdrawing the second stent from the cuff, the cuff will unfold and follow the stent for implantation of the graft.
U.S. Pat. No. 5,800,518 also discloses a graft having a bifurcation for repairing a aortic aneurism. The graft includes a main tubular body and integrally formed first and second tubular legs. The first leg has an opening associated therewith and the second tubular leg includes an lead tube attached to the proximate end. For implementation, the second leg is folded over so that it is oriented in the same direction as the main opening. Then the graft is inserted using a lead tube through the first iliac artery. After the main body is secured to the aortic artery the second leg is pulled into the second iliac artery by pulling on the lead tube.
However, the grafts disclosed in each of these references have shortcomings that make the insertion procedure difficult and time consuming. The present invention is directed to a graft that is significantly easier to insert. None of the references disclose a arterial interluminal graft or method of inserting an arterial interluminal graft according to the present invention as set forth in detail below.
The present invention is directed towards an arterial interluminal prosthesis for repairing an aortic aneurysm of a patient. The aterial interluminal prosthesis includes a main body having a first end with a first aperture that, when inserted into the aortic artery, is located proximate to the renal arteries of the patient. The main body also includes a second end having at least one lower aperture located within the aortic artery and above the entrance to one of the iliac arteries. Preferably, the invention includes two lower apertures that are located in the aortic artery and proximate to the entrances of the iliac arteries of the patient. The invention is also directed to a first leg that is separate from the main body such that it can be inserted into one of the two lower apertures of the main body to extend therefrom into one of the iliac arteries. Further, the invention preferably includes a second leg that is also separate from the main body such that it can be inserted into the other of the two lower apertures of the main body to extend therefrom into the other of the iliac arteries.
In one particular embodiment, the present invention is directed to an arterial interluminal prosthesis further comprising a first stent located entirely within the main body proximate the first end and a second stent coupled at the first end of the main body such that it extends from the main body and across the renal arteries of the patient. Preferably, the second stent is coupled to the first stent and an upper edge of the main body such that it has a restricted lower end and is unrestricted at the opposing, upper end such that the upper end can expand to hold the prosthesis in place.
The present invention is also directed to an arterial interluminal prosthesis having a main body with first and second ends. The main body has a first stent coupled to the inside of the main body proximate the first end and at least one outer stent coupled to the outside surface of the main body below the first stent and proximate to the lower end of the main body. Preferably, the outer stent is coupled to the lower end of the first stent through the wall of the main body.
Preferably, the first, second and outer stents are Z stents. Most preferably, the first, second and outer Z stents are between about 15 and 40 mm, depending on the diameter of the patient""s aorta.
The present invention also includes an embodiment where the arterial interluminal prosthesis has a main body and separate legs further comprised of wall stents in each of the first leg and the second leg. Preferably, the wall stents are substantially the same length as the corresponding legs. More preferably, the wall stents are longer than the corresponding legs such that they extend therefrom to attach to the iliac artery and the main body.
In a preferred embodiment of the present invention, the main body further includes two extensions at the second end for extending towards the iliac arteries. The two extensions have first diameters and the first and second legs have second diameters that are larger than the first diameters to substantially seal the extensions and the main body such that the patients blood flows through the main body and leg members. Preferably, the two extensions further include Z-stents coupled to the outer surface of the extensions and leg members abut the inner surface of the extensions to seal the same.
The present invention is also directed to a method of inserting an arterial interluminal prosthesis into an aortic artery and iliac artery of a patient. The method includes the steps of providing a main body having a first end with an upper aperture and second end having at least one lower aperture and inserting the main body through a first iliac artery into the aortic artery such that the first end is located proximate to the renal arteries of the patient and the second end is located in the aortic artery, proximate the iliac arteries of the patient. Then a first leg member that is separate from the main body is inserted through the first iliac artery and into the at least one lower aperture of the second end of the main body to extend therefrom into the first iliac artery. If two legs are to be used, a second leg that is also separate from the main body is inserted through a second iliac artery and into a second lower aperture of the second end of the main body to extend therefrom into the second iliac artery.
In one embodiment of the invention, the method of inserting an arterial interluminal prosthesis into an aortic artery and iliac arteries of a patient also includes the steps of coupling a first stent to the upper edge of the first aperture of the main body and inserting the first stent into the aortic artery through a first sheath such that the first stent extends across the renal arteries and secures the main body in the aortic artery. Also, the method can include providing wall stents in first and second leg grafts that are longer than the first and second leg grafts and inserting the first and second legs though a second sheath that has a smaller diameter than the first sheath such that the wall stents extend into the main body beyond first ends of the first and second leg grafts such that the wall stents hold the first and second leg grafts to the main body. When the leg members are inserted into the extensions of the main body, the wall stents are expanded such that they abut the inner walls of the main body. Preferably, the leg members are inserted into the main body to approximately the same level. Also, preferably, the wall stents extended beyond the second, lower ends of the first and second leg grafts such that the wall stents hold the first and second leg members to the first and second iliac arteries.